plate armor vs armor plating

plate armor and armor plating both are nouns.

Word	Noun	Adjective	Verb	Adverb
plate armor	Yes	No	No	No
armor plating	Yes	No	No	No

As nouns, plate armor and armor plating are synonyms defined as:

plate armor and armor plating: specially hardened steel plate used to protect fortifications or vehicles from enemy fire

Other synonyms of plate armor include armor plate, armour plate, plate armour.

plate armor (noun)	armor plating (noun)
specially hardened steel plate used to protect fortifications or vehicles from enemy fire	specially hardened steel plate used to protect fortifications or vehicles from enemy fire
a historical type of personal armor made from iron or steel plates, which superseded mail during the 14th century.